Communicating circuits



May 28, 1929. w. A. FLETCHER 5 COMMUNICATING CIRCUITiS Filed Jan. 14, 1924 Zflnessegfl/Z v a; M5 WT-M Tatented May 28, 1 929.

, UNITED STATES- PATEN' OFFICE.

wmrmm ARTHUR FLETCHER, 0]! LOS ANGELES, CALIFORNIA.

' comiumcarme emcurrs.

Application filed January 14, 924. Serial no. 686,196.

the same time the circuit amplifies the signal.

Various further advantages and objectsof the invention will be apparent from the description of a preferred form or example of a circuit embodying the invention. For this purpose there is hereinafter described with reference to the accompanying drawing one form or example of a circuit which embodies the invention. ,7

The drawing is an electrical diagram of the improved circuit.

Referring to the drawing, vided means for impressing upon the circuit the electrical energy or signals to be amplified or rectified. Said means are indicated as provided by an aerial A and a ground connection E, the leadsfrom the aerial A and ground connection E therefor constituting the input leads to the apparatus. Between the aerial A and the ground connectlon E, the circuits are arranged to provide two parallel paths for the energy to be amplified or rectified. One of said paths includes a condenser C and the inductance L The other circuit includes the condenser 0 inductance L shunted by capacity C, and the phones P shunted by the capacity 0 There is also provided means interconnected with the two circuits .thus described for impressing a voltage thereon. Said means includes one or more tri-electrode valves V which are provided with a filament f and two other electrodes 2 and g. If desired,.said electrodes may be a grid 9 and a plate p. ,The filament f of the valve is shown as-heated by suitable means such as current from a battery B. Arheostat 9" is indicated for controlling the temperature of the filament f. The bat.- tery B is indicated as shunted by a potentiometer m, the moving contact of which is connected with the ground E.

The plate p is indicated as connected with one of the parallel circuits being connected to there is pro- 1 said circuit between the condenser C and inductance L The grid g is connected to a grid condenser 0 and a grid leak g to the other parallel circuit being connected in said circuit between the condenser C and L The inductances L and L are shown as inductively coupled together and may be formed as a variometer in which one of the inductances is a rotor while the other is a stator. The condensers C and C together with the condenser C are so related with the inductances L and L that they are adapted to bring these circuits in resonance with the sign'al to be received, amplified and'rectified. The condenser C may have, for example, a capacity of .001 microfarads. The rotor of the condenser C is preferably connected with the aerial lead. The variable condensers C and C may in turn have capacities of .0005 microfarads and the condenser C may have a capacity of .002 microfarads. The grid leak g may have resistances from zero to five megohms. It is understood that in place of the aerial in ground E other means for impressing upon the apparatus the signal or energy to be amplified or rectified can be emplo ed such, for example, as a loop antenna. T e circuit also may be employed in transmission or telephone work. 7

In the circuit thus described the phones P operate as an electro-magnetic rectifier for I the signal. The signal impressed upon the circuit is at the same" time amplified, the extent of amplification depending in part upon the ratio between inductances L and L and also upon the voltages supplied from the valve V. In operation the action of the circuit is entirely stable, no regeneration taking place and all or an of the leads may be inductively coupled 1n part without interference of the operation of the circuit. In order to illustrate the action of the tube V in one form of the invention the circuit was found to operate at maximum efficiency under the following conditions: the plate p of the tube was found to operate at a positive potential of 1 volts withrespect to the filament f. The grid 9 of the tube was found to operate at a positive potential of 5.5 volts. The current flowing through the lines connecting current flows from the filament to boththe plate 32 and the grid 9 and both of such electrodes therefore operate as means for impressing a voltage across the inductances L and L which, in operation, serve to amplify the weak signal voltage from the antenna A.

While the articular form of the invention herein descr ed is well adapted to carry out the objects of the present invention, various modifications may be made without departing from the invention and the invention is of the scope set forth in the following claims.

I claim:

1. A circuit for handling oscillatory electrical energy comprising input leads, a plurality of parallel clrcuits interconnecting said leads, means in said circuits for inductively couplin the'same together, means for bringing eac circuit in resonance with the signal to be handled, a rectifier in one of said circuits, and a tri-electrode valve having its filament connected with 'one of said input leads and having its grid and plate separate- 1y connected to portions of said parallel circuits thereby producing a potential across said inductive coupling means.

2. In a radio receiving c1rcu1t, means for impressing the signal upon twoparallel circuits, means in said circuits for inductively coupling the circuits together, means for bringing each circuit in resonance with the signal to'be handled, telephone'receivers operating also as a rectifier in one of said circuits, and a tri-electro'de valve having two electrodes connected with said parallel circuits whereby the valve operates as a source of electrical potential which is impressed upon the inductive coupling means.

3. A circuit for handling oscillatory electrical energy comprising input leads, a plurality of parallel circuits interconnecting said leads, means in said circuits for inductively coupling the same together, means for bringing each circuit in resonance with the signal to be handled, a rectifier in one of said circuits, and a tri-electrode valve having its filament connected with one of said input leads through a potentiometer and having its grid and plate separately connected to portions of said parallel circuits thereby producing a potential across said inductive coupling-means.

In testimony whereof, I have signed my name to this specification.

WILLIAM ARTHUR FLETCHER. 

